Two latent variable specifications for a manifest regression model. The triangles denote a unit vector, and the directional arrows originating from the triangles represent mean structure parameters (e.g., structural regression intercept, latent mean, or measurement intercept). Parameters constrained to zero (e.g., the δ and ε residuals) are omitted from the diagrams. The top diagram represents a model with the measurement intercepts constrained to zero, and the bottom diagram is a model with the latent means constrained to zero.